Friday, November 20, 2009

http://www.ent.ohiou.edu/~kremer/DER_Project/EarthFriendlyEnergy_Alternatives.pdf

How much energy do we use?
US Average Residential Consumption ~30kWh / day,
or almost 1000 kWh / month
Worldwide: > 12 trillion kWh, increasing to > 21 trillion kWh
by 2020 [Energy and the Environment, Fay and Golomb, 2002]
US: residential energy use
is ~21% of total use
US Energy Production Sources
40% petroleum
25% natural gas
23% coal
8% nuclear
4% hydroelectricity
<1% solar, wind, biomass
[1996 values]

Ammonia-Reforming
Fuel-Cell Vehicle
VW based electric Kit car option: -VW floor pan and mechanicals -Fiberglass body with a low Cd

Primary System Components for
the Ammonia-Reforming
Fuel-Cell Vehicle
•10 kW (13.6hp) PMBLDC Motor
•144V (6.5Ah) Ni-mhBattery Pack
•5 kW PEM Fuel Cell Stack
•Ammonia Electrochemical Reformer
•Motor/Battery/Process/System Controllers
•Heat Regeneration System

Example: A 10-kW wind turbine can generate about 10,000 kWh annually at a site with wind speeds averaging 12 miles per hour,or about enough to power a typical US household. A 1.8-MW turbine can produce more than 5.2 million kWh in a year--enough to power more than 500 households.

WHAT IS LIFESTYLE CONSUMPTION?
It includes “products and services consumed as part of an individual’s day to day life and over which he or she has a degree of choice regarding product, quantity and price ".
Each person’s lifestyle is therefore developed by themselves in daily negotiation with the wider society and the consumer market.
An individual’s lifestyle consumption is composed of:
•House -heating, lighting, appliances
•Transport -cars, buses, flights
•Product consumption -clothes, food, and general
household "goods“
•Example: Home produced vegetables are carbon neutral, average supermarket vegetables have often used up their own weight in fossil fuels

Before I got serious•Total energy use of 2561 kWHover a 12 month period, for a monthly average of 213 kWH. (US Avg. ~750 kWH/month)•Natural gas heating system and high-efficiency heat-pump cooling system controlled by a programmable thermostat•Awnings and trees allow primary cooling to be accomplished via ceiling fans.Initial steps toward conservation:•CFL bulbs tried in some locations•Very low-wattage (4W) "nightlights" used for local lighting

Contemplating Solar Energy Production
Do Conservation first!
•For our current centralized power production system, only
about 1/3 of the input energy makes it to point of use.
Site Analysis –withDovetail Solar and Wind to understand RE
options and determine feasibility of solar and wind systems.
[~2 hours, cost ~ $100 for an estimate and a preliminary design]
Cost/Benefit Analysis: Solar Electric Costs (per Dovetail Solar)
• Complete systems installed:$7-$14/watt
• 1 KW System: usually $9-$12,000
• 4 KW System: usually $28-35,000
• Solar panels: $4-6/watt, make up about 50% of total cost
• Installation: $1-2/Watt, 10-20% of total cost
• Inverter & Balance of System: $2-5/Watt, 30-40% of total cost
•$0.25 kWHaverage cost of solar electric over life of system

Contemplating Solar Energy Production
Sizing a solar system: Sizing can be based on available space, budget, or power production goals.
• 1 kW DC of solar = +/-80-100 ft2(footprint area)
• 1 kW DC of solar ~ 1060 kWH/year or 88 kWH/month avg
1kW rated output at peak sun (1000 W/m2)
x 70%* efficiency
x 4.15** avgdaily peak sun hours per day in Athens OH
x 365 days per year
* Efficiency depends on system components (inverter [avg
15% loss], batteries [10-20% loss], length of
transmission line and voltage level [keep line<150ft])
** Yearly average, winter has only ~ 2.5 daily peak sun hrs

System design: Type of solar panelsSolar panel shortage (Fall 05)Worldwide panel shortage due to the combination of high energy prices and subsidies in Europe, increased solar subsidies causing increased demand in the US, and the shortage of refined Silicon… some panels have 3 to 6 month lead times

Contemplating Wind Energy ProductionWind system: For AWP 3.6at 48V with 7mph annual avgwind speed1.5kWh/day estimated average output [WindCad]Actual data (From a system profiled in HomePowerMagazine):•Summer:~0.5 kWh/day•Fall/Spring:~2 kWh/day•Winter: ~3 kWh/day

Contemplating Wind Energy Production
Wind system:
•Tower height = power (80-120’)
• 30’ over all structures within 300’
• Size matters -large rotors are better
•Property lines, power lines and zoning
• OH is mostly class 2 (9-11 mph)
•More maintenance than solar
•difficult with tower

System-level design issues
Design Goal: overall cost-efficiency and functionality.
Provide an example of what a relatively low cost RE system
can produce for a house not originally designed with
renewable energy in mind sitting on a small ½acre lot.
Questions
•AC vsDC?...AC, with inverter to allow use of std. appliances
•On grid or off?Battery only, utility interactive with battery back-up, or direct grid tie? …Utility interactive to allow net metering and battery backup to provide emergency power.
•To track or not to track?... Adjustable tilt angle is relatively inexpensive, easy and effective (Yes). Tracking the sun is costly and complex but can provide 25-30% improvement (No

System design -Battery bank and Inverter sizing
Considerations
•Running Watts and amount / time of use
•Simultaneous use (what needs to run at the same time)
•Starting Watts (surge capacity of inverters and batteries)
Appliances with electric motors need a much higher startup
surge than they do when running
>1000W for small refrigerators
> 1400 W for some furnace fans
> 12000 W for some well pumps
* Inverter surge capacity varies from 20% to 300%.
* A 3 to 15 second surge rating covers 99% of cases
•Plan to use < 60% of battery capacity (or you will need to
replace batteries often)

My RE System Details
> 960W ground mounted solar array (8 BP SX 120U panels)
> 1kW wind turbine (African Wind Power 3.6 with an
11.6 foot turbine diameter) mounted on a 64 ft high tower
> 2kW grid-connected inverter (Outback FX2000).
> Four 12V Trojan Deep Cycle batteries, series connected
(48 V, 105 Amp hours, ~5KWh storage)
Dovetail Solar and Wind completed
installation of the solar system on
May 31 2004, and the wind
generator in late July 2004.

DOVETAIL SOIAR & WIND, a division ofDOVETAIL CONSTRUCTION COMPANY INC.10760 Hooper Ridge Rd. Glouster, Ohio 457327/16/04, Invoice
8 BP MSX 120Watt Solar Modules
4,800
AWP 3.6 Wind Generator w/ Controller & Dump Load
2,450
64' Tilt-up Tower, Outback Inverter, Charge Controller, Batteries
7,100
Balance of System & Materials
2,200
Installation
4,000
Battery upgrade
180
Plumbing work (required for installation)
50
Tax
$1,017
Total
$21,797

Tracking my energy use and net metering
Date Total Cumulative Actual Sent to Cumulative ProducedProduction Use (kWH) grid (kWH) sent to grid (kWH) June 04 75 KWH 75 KWH July 04 75 150 74.6 Aug. 04 80 230 37.9 42.1 116.7 Sept 04 91.5 321.5 51.5 40 156.7 Oct. 04 61.5 383 47.1 14.4 171.1 Nov. 04 56 439 30.6 25.4 196.5 Dec. 04 63 502 42.8 20.2 216.7 Jan. 05 47.5 549.5 48.7 -1.2 215.5 Feb. 05 81 630.5 49 32 247.5 Mar. 05 132 762.5 46 86 333.5 Apr 05 141 903.5 38.8 102.2 435.7 May 05 115 1018.5 46.7 68.3 504 June 05 112 1130.5 24.5 87.5 592.2 July 05 103 1233.5 42.5 60.5 652.7 Aug 05 96 1329.5 58 38 690.7 Sept 05 113.5 1443 43.5 70 761 Oct 05 75.5 1518.5 53.5 22 783 Nov 05 121 1639.5 41 80 863 Dec 05 76 1715.5 45 31 894

Net Metering Results (Net Energy from grid)Negative meter readings mean a positive net energy balance has been achieved!

My RE System Performance Data Summary:
Average production is less than expected for the hybrid system
•Numerous inefficiencies, still working to reduce them
Max solar output of ~800 Watts DC(85% of rated output)
•~17 amps in full sun around solar noon (48 VDC system)
Max wind output of ~ 1KW
•20 A (1KW) during strong wind gusts -short time durations
•15 A (720 Watts) average during storms
•~3 A (144 Watts) in light winds
Positive net energy balance throughconservation
(~45KWH/month average use compared to 112 KWh average production):
~2000 KWH produced as of March 2006
>1000 KWH sent to the grid as of March 2006

Conclusion: Renewable Energy is Practical in SE Ohio using a modified cost/benefit outlook
Costs:~10K (after grant reimbursements)
Benefits:Besides the fun of seeing the turbine spin and the meter recording negative numbers, other benefits are:
•Effective backup energysystem (maintain power when grid is down)
•All my home power needs are supplied in a renewable and
environmentally friendlyway
•Power productionfrom this system will likely be long term (>30
years) and based on energy prices will produce $100 -$500 worth
of power per year at retail prices (likely payoff period >50 years)
•Provides data on a practical distributed renewable energy system
•Allows me to participate in Education / Communicationactivities
related to Energy

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